A bug in mod_proxy may allow a remote attacker to execute arbitrary code when Apache is configured a certain way.

Background

The Apache HTTP Server Project is an effort to develop and maintain an open-source HTTP server for modern operating systems. The goal of this project is to provide a secure, efficient and extensible server that provides services in tune with the current HTTP standards.

A bug in the proxy_util.c file may lead to a remote buffer overflow. To trigger the vulnerability an attacker would have to get mod_proxy to connect to a malicous server which returns an invalid (negative) Content-Length.

Impact

An attacker could cause a Denial of Service as the Apache child handling the request, which will die and under some circumstances execute arbitrary code as the user running Apache, usually "apache".

Workaround

There is no known workaround at this time. All users are encouraged to upgrade to the latest available version: